The University of Sheffield has led an international team in the world’s first inventory of subglacial lakes.
Dr Stephen Livingstone, senior lecturer in Physical Geography at Sheffield University, led the team which has catalogued data on more than 770 subglacial lakes, some of which were under 3,000m of ice.
The majority of lakes included in the inventory were in Antarctica, but other lakes included were across Greenland, Iceland and valley regions, such as The Alps.
Dr Stephen Livingstone, lead author of the inventory, said: “Innovations in radio-echo sounding, swath radar technology, satellite altimetry and high-resolution time-stamped digital surface models have confirmed the widespread existence of subglacial lakes over the last five decades.
“Our inventory will enable researchers to evaluate subglacial lake environments and their dynamics across different regions. As the ice above subglacial lakes responds to climate change, lakes which were once stable may become unstable, and vice versa.
“Now we have a better understanding of how many lakes are currently stable, we can monitor how this changes with time. These changes are not just important for water and ice flow, but also for the lifeforms that exist in the lakes.”
This inventory has provided a directory of where the lakes are and how they are changing in a warming climate.
Whilst it is believed that there are thousands of subglacial lakes across the globe, there was no specific details on the size, stability and characteristics of the lake until now.
The environments of the lakes, how they behave and the impact on their local areas have also been described in the inventory, which was recently published in the Nature Reviews journal, Earth & Environment, as ‘Subglacial lakes and their changing role in a warming climate.’
As this is the world’s first inventory of subglacial lakes, it has highlighted gaps in collective knowledge that will help researchers focus on new areas.
The team found that 80% of the lakes were stable, and had no addition or removal of water or a balance of inflow and outflow.
However the other 20% were active, which means they can suddenly drain, and so could pose a hazard to human populations and infrastructure downstream.
Dr Kate Winter, senior lecturer in Northumbria University’s Department of Geography and Environmental Sciences, said: “Subglacial lakes are fascinating, they can occur due to meltwater from the surface of the glacier travelling to the base and lying in hollow areas or cavities, or they can occur due to geothermal heating from the earth below, warming the ice above and causing it to melt.
“The lakes are protected by a layer of thick overlying ice which insulates it from the cold air above, preventing them from re-freezing and can exist alone for millions of years, harbouring unique life forms, or they can fill and drain over hourly timescales.”
